1. Field of the Invention
The present invention relates to a bending control device of an endoscope and, more particularly, to a structure of a bending control knob section provided on the control part of an endoscope.
2. Description of the Related Art
In the bending control device of a typical conventional endoscope, an up and down bending control knob (hereinafter referred to as a U-D bending control knob) and a right and left bending control knob (hereinafter referred to as an R-L bending control knob) are coaxially superposed on the control part of the endoscope. Each bending control knob is individually attached to a bending control mechanism in the control part by the use of by, for example, fine screw or a nut.
The prior art suffers, from the following problems. Since each bending control knob is installed by use of a screw or a nut, a screwdriver or a special-purpose tool must be used to attach or remove the control knobs. It is therefore impossible for a doctor to readily change the bending control knobs of the endoscope. It may be necessary to replace the control know with a differently shaped knob depending on the situation or depending on the preference of the doctor using the endoscope. In addition, may be necessary to remove a bending control knob to wash and disinfect it after use since contaminative matter, for example, mucus or blood, may attach to the knob.
Further, since the two bending control knobs must individually be attached or removed using a screwdriver or a special-purpose tool, a complicated and time-consuming operation is needed to replace the control knobs leaving the user (doctor) with considerably troublesome work.
In a conventional bending control device, each bending control knob is detachably provided with an adapter which is larger in size than the control knob. However, it is considerably complicated and troublesome to attach adapters to the two bending control knobs or remove the adapters therefrom. Further since the bending control knobs themselves are not removed, it remains difficult to remove them for washing and disinfection.
In general, the doctor, when handling an endoscope having a control part with two coaxially superposed control knobs, holds the control part with his left hand and operates the control knobs with his right hand. Depending on the situation, the doctor uses either his right hand or the thumb of his left hand to turn the control knobs.
Accordingly, the conventional bending control device of the type having coaxially superposed control knobs on the control part has the disadvantage that contaminative matter is transferred from the right hand, contaminated by contacting the insert part which may have been inserted into a hollow organ of the patient's body to the left hand via the bending control knobs. The results in the whole control part being contaminated. Therefore, it is necessary to disinfect or sterilize the control part by dipping it in a disinfectant or sterilant before each use. This endoscope disinfecting operation is extremely complicated and time-consuming. Since at least 30 minutes is needed to complete each single disinfection, another endoscope must be used for examination of the next patient, and it is therefore necessary to prepare a plurality of endoscopes in order to conduct examination of a large number of patients.
If the disinfection or sterilization of the control part is insufficient, there is a fear that bacteria and viruses may be transmitted from one patient to another through the contaminated control part.